diff --git a/packages/swap-router/src/swap-simulator/utility/tick.util.ts b/packages/swap-router/src/swap-simulator/utility/tick.util.ts
index 4d9bf8ed7..01d1fc86a 100644
--- a/packages/swap-router/src/swap-simulator/utility/tick.util.ts
+++ b/packages/swap-router/src/swap-simulator/utility/tick.util.ts
@@ -102,7 +102,7 @@ export function nextInitializedTickWithinOneWord(
   if (isTickToLeft) {
     const { wordPos, bitPos } = tickBitmapPosition(compressed);
     const mask = (1n << BigInt(bitPos)) - 1n + (1n << BigInt(bitPos));
-    const bitmap = BigInt(tickBitmaps[wordPos] || 0n);
+    const bitmap = BigInt(Number(tickBitmaps[wordPos]) || 0n);
     const masked = bitmap & mask;
 
     const initialized = masked !== 0n;
@@ -114,7 +114,7 @@ export function nextInitializedTickWithinOneWord(
 
   const { wordPos, bitPos } = tickBitmapPosition(compressed + 1);
   const mask = ~((1n << BigInt(bitPos)) - 1n);
-  const bitmap = BigInt(tickBitmaps[wordPos] || 0n);
+  const bitmap = BigInt(Number(tickBitmaps[wordPos]) || 0n);
   const masked = bitmap & mask;
 
   const initialized = masked !== 0n;